Is there a way to nest transfer functions?

Question

Matthew Mishrikey 2021-12-28

回答： Matthew Mishrikey 2021-12-28

I wish to build up a transfer function inside a for loop such that each iteration builds up a new transfer function based on previous iterations.

This would look like ftest = 1/(sC3 + 1/(R3 + 1/(sC2 + 1/(R2 + 1/(sC1 + 1/R1)))))

I tried something like this

ftest = 0 ; ftest = tf(1, [c(length(r)) (1/r(length(r)) + ftest)])
ftest = tf(1, [c(length(r)-1) (1/r(length(r)-1) + ftest)])

But if you include a transfer function in the denominator tf just ignores the denominator.

The impedance of an n-pole cauer model takes this format!

Answer 1

Matthew Mishrikey 2021-12-28

Okay, nevermind, found the solution is to use s = tf('s') rather than tf([num dem]).